Evaporator



Oct. 25, 1932. J KERMER 1,884,726

EVAPORATOR Filed May 27, 1929 1 valuables.

Patented Oct. 25, 1932 UNITED STATES PATENT OFFICE MARTIN J. KERMER, FBUFFALO, NEW YORK, ASSIGN'OR TO BUFFALO FOUNDRY & MACHINE COMPANY, OFBUFFALO, NEW YORK, A CORPORATION CF NEW YORK EVAPORATOR Applicationfiled May 27,

This invention relates to an evaporator which is more particularlydesigned for evaporating milk although the same can also be used forremoving or reducing the water content from the solids of other liquidmixtures.

It is one of the objects of this invention to provide an apparatus ofthis character which is comparatively simple in construction andtherefore permits of making the same of more expensive metals, such asnickel and stainless steel which ordinarily is too eX- pensive for usein constructing evaporators in accordance with the designs heretoforeknown. a i j P Another object of this invention is to so organize theevaporator'that the entrainment of solids in the vapor drawn off isreduced to a minimum, thereby avoiding waste of the Further objects ofthis invention are to provide means whereby the evaporator or heatingtubes can be thoroughlycleaned and also readily and convenientlyreplaced when necessary, andalso to provide simple and efficient meansfor reliably supporting the evaporator in its operative position.

In the accompanying drawing:

Figure 1 is a vertical longitudinal section of an evaporator embodyingmy improvements.

Figure 2 is a fragmentary verticaltransverse section of the same takenon line 2, 2

Fig. 1.

Figure 3 is a horizontal section taken on line 3, 3 Fig. 1 lookingdownwardly.

Figure is a horizontal sectiontaken on line 4, 4t Flg. 1 lookingupwardly.

Figure 5 1s a fragmentary vertical section on an enlarged scale showingthe manner of welding together the parts of the dome and securing theevaporator tubes in the flue sheet of the dome by welding.

In the following description similar characters of reference indicatecorresponding parts in the several figures of the drawing.

The numeral represents the dome of the evaporator which may be variouslyconstructed but as shown in the drawing the same preferably consists ofan upright cylin- 1929. Serial No. 366,143.

drical sheet metal body 11, an upwardly dished crown 12 secured at itsperipheral edge to the upper edge of the sheet metal body 11 by means ofa welded joint 13, and a sheet metal flue sheet 14 forming the bottom ofthe dome and secured adjacent to its marginal edge to the lower edge ofthe sheet metal wall 11 by means of a welded joint 15.

Projecting downwardly from the central part of the dome top anddiametrically across the upper part of the side wall is an upright mainbathe 16 preferably made of sheet metal and terminating at its loweredge at a distance from the bottom or flue sheet 14: of the dome so asto form a horizontal passage between the inlet chamber 17 within thisdome on the front side of the balile 16 and the outlet chamber 18 withinthis dome in rear of the baiiie plate. The upper part of the outletchamber 18 is provided with a vapor outlet 19 through which the vaporsare withdrawn from the apparatus and which is pref-v erably connectedwith an exhausting device of any suitable character so as to create a.vacuum whereby these vapors are forcibly withdrawn from the outletchamber of the dome.

The numeral 20 represents a plurality of upright evaporator or heatingtubes which are arranged to form a cluster or bundle uni erneath thefront part of the dome and which open at their upper ends into the lowerend of the inlet chamber 17 of the dome in front of the baffle plate 16,this being preferably accomplished by extending the upper end of each ofthese tubes into an opening 21 (see Fig. 5) in the flue sheet 14 and securing these parts together by a welded joint 22, as shown in Figs. 1and 5, or by expanding these tubes in said openings or securing the sametherein in any other suitable manner.

The lower ends of these evaporator tubes are likewise secured by weldedoints 28, eX- pansion or otherwise, in openings formed in the lower fluesheet 24, which forms the top of a manifold or liquid chamber 25arranged below the cluster of evaporator tubes. These tubes are heatedon their exterior by a heating medium of any suitable character, but

of the tubes and is secured at itsiupper edgeto the underside of theupper flue sheet 14, and a comparatively long lower section 29surrounding the lowerpart ofthe tubes and connected at its upper endwith the lower end of the short chest section 28, while its lower end isconnected with the lower flue sheet 24. Y

The upper short steam chest section 28 is arranged eccentrically withinan outer sup porting ring 30 of larger diameter which 25i latter issecured at its upper edge to the marginal part of the underside oftheupper flue. sheet 14 and is preferably made int'egrally of cast metalwith the small inner supporting ring 28 which constitutestheupper'sectionof the steam chest. These inner and outer rings 28 and30 therefore-form a convenient and reliabl'emeans for supporting'theevaporator at a point adjacent to the upper end thereof on the beams,pedestals or: other sustainihgpant of the building.

To permit of' thus supporting the evaporator, the outer large ring 30 isprovided at different points of its periphery with laterally projectingbrackets or'feet 31 which are adapted to rest on the beams or otherconvenient supports of the'structure in which the evaporator is housed.

' The liquid to be evaporated may be supplied to themani f ol'dorliquid'sp aee25 below the tube cluster in anysuitable manner for instancethrough a pipe 32' opening intothe side wall of this manifold 25 and theliquid discharged by the tubes 20 intothe dome 10 i s-returned' from thelatter tothe lower mani fold 25=by adownta'ke, which in the presentinstance preferably consists of an upright section 33 connected at itsupper end with the upper flue sheet 1%,. and" communicating" with thelower end" of the dome in rear of the main baffle 1 6, and a lower elbowsection connecting the lower end of the upright downtake section 33 withthe sideof" the lower manifold 25. The height of the liquid undertreatment within the evaporator may be observed by means of a glass gage35' connected with the upri'glit section of the d'owntake.

As the liquid is heated in the tubes 20' it starts to boil, whereuponthe'resulting-vapor and liquid will be discharged upwardly from theupper ends of these tubes into the inlet section or chamber 17 of thedome, the top of which is normally closed. In the upper part of chamber17 is formed a vapor cushion. When the mixture of liquid and vapor isdis charged into this-chamber; 17 by the tubes 20, the heavy particlesof liquid will'penetrate this cushion of vapor and may be depositedagainst the walls of the chamber 17, while the vapors are reflected bythis cushion and flow through the passage under the battle 16intochamber 18. Also due to the constant discharge of the mixture ofliquid and vapor from tubes 20,.the vapor cushion formed directly abovethe tubes will be forced laterallyadjacent tozopposite vertical: edgesof the hafiie. 16 and displace. some of the vapor in these spacesmarked'50in Figs. 2: and 3:, thereby forcing the vapor-under'the bafileand into the: chamber 18.. During: such discharge of the liquid andvapor by the tubes 20 into the inlet chamber 17 the liquid and vapor areseparated and-some of the liquid will adherev to the internalsurfacesof; the inlet chamber 17' formed by the adjacent part. of the wall. 11',the crown 12 and the main baffle sheet. 16, and flow downwardly on.these surfaces toward the" bottom: of. the dome. In order to prevent.the liquid which flows downwardly along the front portion of the wall 11of. the dome from-interferingiwithl, the upward discharge of liquidandivapor from the tubes 2.0 into'the inlet chamber-I,1-7;,.a-nauxiliary baffle 36 is provided; which; is preferably curved; andmounted on the upper side of the upper flue sheet 14: between the front.side of. the tube; cluster 20 and the adjacent front por tion ofthe wall11', as best shown in Figs. I and 3, this; auxiliary baflie beingpreferably curvedso; that any liquid which flows fromthe front part. ofthe. domewall 1 1 will be deflected laterally and rearward alongoppositelateral sidesv of the cluster of tubes 20, from. whence the same flowsback into the upper end of the downtake 33- without liability of flowingtoward the upper ends. of the tubes 20 and interfering with thedischarge of liquidand vapor from the latter.

The vapor which is separated from the liquid the: inlet chamber orsection 17 of the dome passesf-romthe lower end of. the latterrearward'ly through the passageway be tween the lower end of the bafile1 6 and the upper fluev sheet 14L into the lower end of the outletchamber or section 182 of the dome, thenceupwardly and through theoutlet 19 at upper end of the outlet chamber 18., while the liquidpasses from the lower rear part of; the dome into the downtake and isreturned by. the latter to the manifold 25 preparatory to again enteringthe lower ends 'of' the evaporator tubes and being heated therein againand discharged into the inlet chamber of the dome, this operation beingrepeated" continuously and the unevaporated A liquid being circulated inthis manner while the apparatus is in use. The passage-way connectingthe lower ends of the inlet chamber 17 and the outlet chamber 18 of thedome is so constructed as to provide the maximum cross sectional area inthis passage-way and permit the maximum flow of vapor from this inletchamber to said outlet chamber without permitting any of the liquidwhich is being discharged upwardly from the tubes into the inlet chamberfrom llqeing thrown directly into the outlet cham- Inasmuch as the vaporand liquid issue or spout from the upper ends of the tubes 20 in theform of an upwardly enlarging cone, stream or blast, the central loweredge portion 87 of the bai'lle plate 16 is made longer than the sideportions 38 of the same, this central extension 37 being near to theupper ends of the evaporator tubes forming the inner or rear part of thecluster and thereby prevents the spreading vapor and liquid as it issuesfrom these rear tubes from being thrown directly from these tubes underthe lower edge of the baffle 16 and into the outlet chamber 18. Thoseportions 38 of the lower edge of the baffle 16 on opposite sides of thecentral part 37 thereof are, however, farther away from the upper outletends of the cluster of tubes 20 and these lower edge portions 38 aretherefore cut away, preferably on a curve or other suitable form, sothat the lower edge of this bafiie diverges upwardly from the centralpart of the same toward opposite vertical edges thereof, so that aconnecting passage is formed between the chambers 17 and 18-which iscomparatively low at the center, as shown at 19, and comparatively wideat its opposite ends, as shown at 40 in Fig. 2. The fullest possiblefreedom is therefore provided for the escape of the vapor from the inletchamber 1'? to the outlet chamber 18 without liability of liquid beingspouted from the tubes 20 directly into the outlet chamber 18; Thevelocity of the vapors entering the inlet chamber 17 and passing intothe outlet chamber 18 is therefore reduced, whereby entrainment ofliquid in the stream of vapor is cor *espondinglv reduced. Thecomponents of the velocity are still further changed as the vaporchanges its direction in passing around the lower edge of the baifle 16and thence upwardly from the lower end of the outlet chamber 18 to theupper end thereof, inasmuch as thevapor at this time completely reversesthe direction in which it flows and the component of the velocity risesfrom zero to its maximum in the top of the dome thus rendering itimpossible for liquid to become entrained in the same.

In passing from the tubes 20 to th vapor outlet 19 the vapors changetheir direction three times, first in the inlet chamber 17 from anupward direction to a downward direction, next below the baiile 16 froma downward direction to a horizontal direction, then in the outletchamber 18 from a horizontal to an upward direction.

By means of these repeated changes in the direction of the flow of thevapors the particles of liquid are projected by their inertia onto thewalls of the dome and the baflie 16 of the evaporator, where they havean opportunity to flow together and be collected by the means providedfor this purpose.

For the purpose of still further reducing the possibility of entrainmentof liquid in the vapor as the vapor passes from the inlet chamber to theoutlet chamber 18, means are provided whereby the liquid separated fromthe mixture and flowing downwardly on the front side of the bafile 16 isprevented from dropping ofl the lower edge thereof acrossthe entirewidth of this baffle which otherwise would formia continuous sheet,curtain or stream of liquid across the entire dome. The preferred meansfor accomplishing this consists of two gutters 39 arranged on the lowercurved portions 38 of the baiile 16 and inclining from the side of thedome downwardly toward the central extended part 37 of the baffle 16,the opposing-inner ends of said gutters being spaced apart anddischarging into a downwardly projecting spout 51 which is formed onthis central downward extension 37 of the main battle and thereby servesto deliver the separated liquid close to the upper side of the upperflue sheet 14: forming the bottom of the dome so that the possibility ofentraining liquid in the vapor is reduced to a minimum. 7

As a result of this construction the liquid striking the front side ofthe baflie 16 will flow downwardly thereon toward the lower edgethereof, that part of the liquid on the central part of the baiiieflowing directly from the lower edge 37 thereof on to the central partof the upper flue sheet 1 1, while those parts of the liquid flowingdown the lateral or side portions 38 of the baffle 16 are caught by thegutters 89 and directed toward the spout 51 on the center of this bafiiewhere -1 it is also discharged upon the central part of the upper fluesheet, thereby leaving the two enlarged side portions 40 of thepassageway between the inlet chamber 17 and the outlet chamber 18unobstructed by any streams or sheets of liquid, and permitting thevapor to pass from the inlet chamber to the outlet chamber withoutpassing through any shower or sheet of liquid thereby avoiding thepossibility of entrainment of liquid in the vapors at these points.

Another important function of the large flat plate 14 forming the bottomof the dome, especially when concentrating milk products,

is that it acts as a deodorizer. A thin film of 5 also'be apparenttliatthe upwardly divergent ture which. makes'it possible to-drive oilconsiderable of objectionable flavors.

lVlien the liquid has been. concentrated to the: desired: point thesame; may be removed through the; outlet 41' which is preferably formedin the lower part of the downtakev and connected with a. pump. or othermeans ofthe manifold 25 which; is normally closed for removing theliquid as desired.

' For the purpose of cleaning the tubes when required, the same arefilled with water up to theupper flue sheet 14, an attendant-then entersthe inletcha-mber of'the dome through a manhole 42' which is normallyclosed by a cover 43 and operates upon the tubes from the upper end:thereof by means of a brush which permits of thoroughly cleaning thesame. In like manner the operator can enter the-outlet chamber1-8'through a man-hole 44: which is normally closed by a cover 45 forthe purpose of cleaning the downtake 33, 34 by means of a brush or othersuitable utensil. The removal of the refuse from the apparatus which hasbeen thus detached from the evaporator tubes QO-and the downtake may beeffected through. an opening in the lower end by a door i6. 7

Whenever the tubes 20 require repairing or renewal thesame may beremoved from the apparatus or access may he had thereto through anopening 47 in the top-or crown of the dome which is normally closed by acover48;

It will therefore be apparent that this construction of evaporatorpermits of thoroughlycleaning all parts of'thesame and therebymaintainthe apparatus in the most sanitary condition so that theproduct. resulting-from its usewil-lbe ofthehi'ghest quality. It willlower edge of the ballie 16 will permit the vapors to flow freely awayfrom the inlet chamber- 1*? to the outlet chamber 18,. and thatthegutters and spout formed on the side and central portions ofthi's-bafiie. plate provide cross-sectional passage areas which. are

. unobstructed by liquid, thereby enabling the vapors to flow away'at areduced velocity and under conditions least liable to; entrain anyliquid therein. I

Onaccount of the simplicity of the constructi'onof this apparatus it ispossible to make the main parts of the dome, such as the body, crown andupper flue sheet of expensive metal, such as nickel and stainless steel,and

to weld these members to each other and also to weld or otherwiseconnect the flue sheets smootlr joints between these members; which willreduce to a minimum the possibility of any of .thematerial undertreatment from lodgingwithin: the apparatusand therebyrendering' the:same'highly sanitary.

It will benoted that in this construction the heating tubes 20 are muchlonger than the height of the inlet chamber 17 of the dome so that theliquid will be heated rapidly and discharged at a. high velocity fromthe upper ends of saidz tubes and the upper closed part ot the inletchamber 17 is; of considerable height so that the same will hold a vaporcushion of substantial size intowhich the heated liquid is discharged bythe heating. tubes and a separation. is effected within this inletchamber: between the liquid and any vapors which have been formed.

I claim as my invention:

1.. An evaporator comprising a dome, a

baille' extending downwardly from the topof the dome andv terminatingshort of. the bottom thereof, heating tubes opening into the lower partof said dome 011 one'side of the-baffle, a liquid return at the lowerpart of said dome onthe opposite'side of said baflle, a vapor outlet atthe top of said dome on the same side of the baffle as the liquid:discharge, an outer large ring supporting the bottom; of said dome towhich the upper ends of the heating tubes are connected,'and asteamchest surrounding said tubes and, including an inner small ring arrangedeccentrically withinthe large outer ring and formed integrally therewithand serving as asupport for said steam. chest.

2. An evaporator comprising an upright dome, avertical imperforatebafile arranged in said. dome diametrically across the central partthereof and dividing the space within the dome into an inlet chamber andan. outlet chamber and said baflle being connected at its upper end withthe top of the'dome and connected at its opposite vertical edges-withopposite sides of the dome and having one part of its lower edgedepressed and arranged close to the bottom of the'dome so'that liquidonthe inlet chamber side of the baffle flows from the depressed edge ofthe same to thebottom of the dome, while another part of said lower edgeis raised aconsiderable distance above'the bottom of said dome and.forms an enlarged passage through which the vapors, pass from theinlet'chambcr to the outlet chamber of the dome; a: plurality of uprightheating tubes having their upper ends secured to thebottom of said domeand. opening into said inlet chamber, a heating chest surrounding saidheating tubes a liquid supply chamber communicating with the lower endsof said. tubes, and a return pipe connecting said outlet chamber withsaid liquid supply chamber, said heating tubes being longer than theheight of said dome so that the liquid heated therein will be dischargedfrom the upper ends of said tubes at a high velocity into the upperclosed part of the inlet chamber and said inlet chamber being of suchheight that a Vapor receiving space of considerable height and closed atits top is formed directly above the heating tubes, Which vapor space isadapted to hold a vapor cushion of substantial volume into which theheated liquid is discharged upwardly from the tubes and a separation ofthe Vapors and liquid is eiiected therein.

In testimony whereof I hereby aifix my signature.

MARTIN J. KERMER.

